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Daniel Mahr – Glass Box Quant at MDT Advisers (EP.472)

from Capital Allocators – Inside the Institutional Investment Industry

55m 47s

Daniel Mahr – Glass Box Quant at MDT Advisers (EP.472)

Daniel Marr, head of MDT, Federated Hermes' $26 billion quantitative equity group, discusses his career path and investment approach with Ted Seides on Capital Allocators. Dan began flipping hot IPOs as a Harvard undergraduate, an experience that taught him the value of disciplined, systematic investing after early losses from straying beyond his expertise. He joined MDT Advisors in 2002, working closely with founder David Goldsmith, and took over leadership in 2008. MDT pioneered a decision tree approach in 2001, evolving from simple factor tilting to a sophisticated machine learning framework. Dan describes this as a "glass box" rather than a black box, emphasizing transparency so the team understands what drives every trading decision. The firm uses a forest of shallow trees, typically asking two to five questions per tree, to avoid overfitting while capturing nuanced interactions among factors like financing, momentum, volatility, and company age. A central theme is the role of human emotion. Dan recounts how his head of trading regularly wanted to override purchases of stocks down 70-80%, illustrating why the strategy works: even quantitative investors struggle to buy bad stories. MDT focuses on analytical edge rather than informational edge, training models on roughly 50 years of data. Dan also discusses leverage-driven quant blow-ups, changing market structure, recruiting challenges, and his passion for home brewing sour cherry beers.

Transcription

8535 Words, 48735 Characters

English
Speaker 1our head of trading would come to me every day we bought a stock that was down 70 or 80% and say, Dan, we need to override this trade. The company's CEO just resigned in disgrace. Dan, this is a one product biotech company and they just missed their target. It looks like the whole company's got nothing. We have to override these trades. We can't do them. That's when the light bulb goes off. This is precisely why this strategy works is because even quantitative investors who are intentionally trying to buy these stocks find it hard to overcome the human emotions involved with buying a bad story.
Speaker 2I'm Ted Seides, and this is Capital Allocators. I guessed on. Today's show is Daniel Marr, head of MDT, the $26 billion quantitative equity investing group at Federated Hermes that oversees a suite of actively managed mutual funds, ETFs, collective investment trusts, and separately managed accounts. Dan joined the firm in 2002 as a junior analyst and took over leadership of the team six years later, guiding its evolution through vast changes in data, computing power, and investment methodology. Our conversation today is going to be a little bit different. The conversation traces Dan's path from flipping IPOs as a college student to running machine learning models across global equity markets. We discussed the development of MDT's decision tree framework, a glass box approach to stock selection that blends transparency with sophistication, and how the team balances analytical rigor with human judgment. Dan explains lessons from two decades of modeling markets, including the challenges of overfitting and underfitting data, and MDT's steadfast focus, an analytical edge rather than informational edge. Before we get going, it's that time of year when we turn to traditions, like the tradition of Thanksgiving, gathering family and friends to share what we're thankful for. One of which is the ability to eat enough turkey and tryptophan to fall into one of the best slumbers all year, that nap on the couch while watching football. While I'll spend the turkey days with my family, I'm particularly grateful this year for the incredible team of professionals who have helped me get through this difficult time. I'm also grateful to the team of people who have helped me get through this difficult time. I'm also grateful to the that brings together what you hear and experience with Capital Allocators. That's Hank, our CEO, Morgan, our head of ops, Tamar, our head of business development, and Liz, our head of content. I'd put our starting five up against any NBA all-star team. Off the court. Our values of quality, entrepreneurial spirit, intellectual curiosity, respect, generosity, and fun win championships. Although I can't say the same about the team of professionals, I'm grateful to the team of professionals who have helped me get through this difficult time. I'm also grateful to the team of professionals who have helped me get through this difficult time. Although I can't say the same On the court, for my getting dunked on, because at 6'1", I'm the least vertically challenged of our starting five. Outside the office, I'm grateful for you, for listening, engaging with our guests, and sharing kind words all year long. This podcast is the gift that keeps on giving. So before you start the mad year-end dash to calculate performance, conduct 360 reviews, and shop, take this time to be grateful for the many gifts in your life. As my friend Dasha Burns recently shared, On the occasion of my 55th birthday, may the best of your yesterdays be the worst of your tomorrows. While you're feeling all warm and fuzzy, don't forget to spread the word about capital allocators to those closest to you, to give them the gift that keeps on giving. Please enjoy my conversation with Daniel Marr. Dan, great to be here with you. My pleasure. I'd love you to take me back to your original path leading into your involvement in investing.
Speaker 1I was a kid. I was a kid who loved numbers. I'm old enough that my parents subscribed to a physical newspaper every day, and I would pour through every section that had numbers, whether it was sports or business. When I get to college, I had my first experience with investing. I was a freshman at Harvard in 1998, going into 1999. I came across the realization that there was an interesting opportunity to be had, which was that there were a lot of people who were interested in investing, and they were interested in investing. And they were interested in investing. And I was one of them. They would go up 100%, 200% or more on the day that they priced. And there were a small number of investment firms that would get allocations to these IPOs, and they would offer them first come, first serve. As a college student, I had a faster internet connection than just about anyone else in the world. And I had a lot of flexibility in terms of my time. I managed to get a number of allocations to those hot IPOs. You'd get 100 shares. But as a college student, that seemed like great money. I studied computer science, was really interested in being a software developer. As I pursued the internships, I realized what was really important to me was that I found the industry and the work and the product to be exciting. I had a summer internship where I was building mobile internet apps, which you might think would be exciting until you remember what a phone was like in the year 2000. As I progressed, I realized that the quant investing was a field where I'd be able to blend the investment markets with my software background and have them look
Speaker 2back. So in that period of time, you're flipping hot IPOs. There's a lot happening around the internet, a lot of excitement. How did you think about leaning into that compared to leaning on the quantitative background and going into finance that way?
Speaker 1The experience of being invested in those IPOs made me convinced that I was a great technology investor. For as much as those 100 share allocations led me to some nice wins in my portfolio, I would then translate it into some giant losses by straying from the original thesis and believing that I was an expert in something that I was certainly not. That experience was also very formative in my appreciation of a more disciplined, systematic, rigorous approach to investing, which I found in the quant space. So how'd you get started? I joined a firm called MDT Advisors in 2002 as a junior analyst. MDT was a pioneer in the quant investing space. They had been building a strategy since 1991, very early practitioners of quant investing. I worked closely with the founder of the strategy, for a number of years. We were acquired by a firm, Federated Investors, now Federated Hermes, in 2006. I took over running the team when the founder retired in 08.
Speaker 2If you look at the long history of quant, and you can go back to MDT's founding in the early 90s, how do you think about what's the same and what's changed in the application of quantitative
Speaker 1investing? One thing that people sometimes miss about quant is that there's a lot of diversification in terms of quant strategies. There are certainly folks out there who are still applying strategies that are very similar to what was applied in the early days, the early types of quant strategies. But over the decades, there's been such an explosion in processing power, in data, in algorithms that marry those two things. The types of strategies and the sophistication of strategies, like Miran, has really exploded over the years, aided by those tailwinds of processing and data.
Speaker 2I'd love you to walk me through your journey of what the investment strategies looked like using the quantitative tools available when you joined in 2002, and how that's evolved to today.
Speaker 1In 2002, we had made a big transition at MDT. For the first decade, the strategies were traditional factor tilting. There was a formula that used a small number of characteristics, and the portfolios would tilt toward them. Those strategies generated a pretty good outcome, but it was lumpy. As with many quants, the strategies had a difficult time in 1998, 1999, as value and quality was not well rewarded by the market. The firm started looking for a differentiated approach, something that wasn't reliant on the factors always working because the market was not well-rewarded. The portfolios were always tilted in the same way. That led us to the decision tree approach that we still use today, albeit in a much evolved way from where we started in 2001.
Speaker 2Why don't you walk me through what that means, a decision tree approach applied to stocks?
Speaker 1So a decision tree, these are things that people have probably seen. It's just a series of yes and no questions about characteristics that lead to a forecast. Or an outcome. A common place that they're used is in an insurance setting. In the life insurance industry, you may want to build a model to predict longevity. Decision trees are often used in that space. The first question might be on age. Depending on how you answer that question, whether you're above or below a certain age, there will be differentiated questions that are asked to help provide the most precise decision. The second question might be on age. Depending on how you answer that question, there will be differentiated questions that are asked to help provide the most precise decision. The third question might be on age. The fourth question might be on age. Depending on how you answer that question, there will be different than for people who are under the age of 65. If you're a smoker, there will be questions about how much do you smoke? How long have you been smoking? That won't be relevant of people who don't have that characteristic. Translating that back to the stock world, instead of asking about risk factors for longevity, we're asking about the characteristics of companies. And depending on how those questions are answered, the lines of questioning will evolve based on what's relevant of those types of companies.
Speaker 2Before we dive into that approach, I'd love to take a step back and ask how you think about an investment philosophy tied to quantitative investing. In particular, what do you believe that leads its way into your investment approach?
Speaker 1Very succinctly, what we believe is that a disadvantage of investing in a stock market is that it's not going to be a good thing. It's not going to be a good thing. It's going to be a bad thing. A disciplined, quantitative approach to stock picking can lead to an analytical advantage that will help us generate superior portfolio outcomes in the sense of generating more all-weather type portfolio returns.
Speaker 2And what is it about the analytical approach that leads you to believe that?
Speaker 1When you think about how do you construct a portfolio that is going to be able to perform well in lots of different ways, different market environments, there's two approaches to doing that. One is to be able to predict what the market environment is going to be with a fair degree of accuracy and then tilt your portfolio ahead of time to be in the right stocks, the right sectors at all times. Global macro crystal ball approach. There are investors who do that. It's not in our wheelhouse at all. The other approach is very much on the other end of the spectrum of leaning on diversification, of not having reliance on any one company, any one sector, any one type of stock to be able to drive your portfolio outcome and to diversify across companies with differentiated alpha drivers gives you that opportunity to have a portfolio where you'll have a fighting chance at no matter what market environment comes.
Speaker 2In a world with much more computing power than we've had in the past and more people able to look at these types of strategies, how do you think about what differentiates your approach and how you think about it from other participants in the market?
Speaker 1What differentiates us at MDT is the use of machine learning. AI and machine learning are very hot topics right now. I read academic journals. I see what's going on in the world. I see what's going on in the space. I see what competitors in the space are publishing. There's a lot more enthusiasm than there was five years ago for competitors in the space to be adopting or at least researching using some of these technologies. But that said, at MDT, we've been using these machine learning tools since 2001. We have a 24-year head start on someone who is new to the game. We have learned a tremendous amount over the last 24 years on what the advantages, but more importantly, what the potential pitfalls are of using these powerful but also finicky and sometimes misled algorithms in a noisy data space like forecasting stock returns.
Speaker 2What are some of those important pitfalls that you've learned along the way?
Speaker 1There are a pair of very related issues in the data science space, which are overfitting and underfitting. Obviously, they're two sides of the same coin. It's easy to not build a model that's overfit just by having a very simple model. But that very simple model is going to leave a lot of explanatory power on the table. It's going to be underfit. That's a problem that gets less press than overfitting, but is a significant one nonetheless. Figuring out what tick techniques can allow us to strike the right balance between having a model that's too complex versus having a model that's not complex enough is something that we have put a lot of thought into and evolved significantly over the decades. Our view in the machine learning space is that transparency is exceedingly important to understand precisely how these models are working. A common epithet that gets thrown, at us in the quant investment management space, is that we're using black boxes. At MDT, that is not the case. We like to position our investment strategies as being a glass box. There's a lot of machinery on the inside, but we can see into it. We can see how it's working and understand what's driving all of the decision making on a day-to-day basis.
Speaker 2But Kirish, how do you go about doing that when computer programs go to be the human? It makes a move that nobody really understands. So there's this power of the machine learning, figuring something out that you couldn't as a human, which also means it would be hard to know what it is. So this balance between the black box and the glass box.
Speaker 1The algorithms behind AlphaGo are not a decision tree. Machine learning, one of the advantages of that field is that it is able to discover insights on its own. And generally speaking, when we're doing a decision tree, we're not going to be able to figure out a new research idea that makes it into the model. We ex-ante have figured out why this idea, we expect it to add value or not. Occasionally, we're modestly surprised by what comes out of the research process. A number of years ago, we started adding price-based factors to our model. And the price-based factors found momentum effects, as was published in the academic literature. And as we fully understand, we're able to figure out what's going on. And we're able to figure out what's going on. And we're able to figure out But it also found some very powerful reversal effects for companies whose share prices were down 70 or 80% over the last year, in combination with other characteristics, such as value and quality, could lead to strong outcomes. We didn't quite have a feeling for it, but we beat up the data and we convinced ourselves that it was worth implementing. As soon as we started trading stocks that fit that profile, it immediately became obvious, because our head of trading would come to me every day, we bought a stock that was down 70 or 80% and say, Dan, we need to override this trade. Dan, this is a one product biotech company, and they just missed their target. We can't do them. This is precisely why this strategy works. It's because even quantitative investors who are intentionally trying to buy these stocks find it hard to overcome the human emotions involved with buying a bad story.
Speaker 2I'd love to tease through how you go about the investment process. I'll just go top to bottom. As you're building a model to try to understand what stocks are likely to outperform, how do you come up with the ideas that you want to test quantitatively? There are two big
Speaker 1sources of research ideas for our process. Certainly, we read all of the academic and practitioner literature in the investment finance space. Occasionally, we get some good ideas out of seeing what's published. More often than not, we test an idea, and either it's not a good idea, or it's not a good strategy, or it's a bad strategy, or it's a bad strategy, or it's not a good strategy, or it's not a good strategy, or it's not a good strategy, or it's not a good strategy. So our model essentially captures the same underlying effect. Where we find more value typically is when we generate ideas that are driven by our own observations on the behavior of our strategies. That's one of the advantages of having the long history. We've been investing our strategies over 30 years now. The observations that we've made across multiple different market cycles over those decades, we've been able to test them. We've been able to test them. We've been informed meaningful enhancements to the process.
Speaker 2When you build out your model, do you start with a couple of core factors that you believe true all the time, and then build from there? As you build the model, how do you construct what those inputs are?
Speaker 1It's driven by machine learning, which leads us to a differentiated view on factors to a lot of other investors. One of the most unusual factors that we use, we call company age. We measure that simply as how long has the company been publicly traded and or filing financial statements. It's an unusual factor. To the best of my knowledge, few quant investors use that in their models. Also, very few, to my knowledge, traditional portfolio managers explicitly take the company's age into account when they're formulating their model. So it's a lot of different things. And there's a reason for why it's unusual, which is that on its own, Company age tells you nothing about whether a company is going to outperform or underperform. Companies don't stop performing well because they've hit some magic number of years since their IPO. Why do we use this factor in our model? The power of the decision tree is that it allows you to make use of factors that don't explain returns on their own, but can give you context on to how to explain returns. What we find is that the important questions to ask about young companies, companies that are within 10, 15, 20 years of their IPO, are a little different than the important questions to ask of companies that have been around for 50, 80, 100 years. The decision tree gives you that framework to say, if you're a young company, let's ask these questions. But if you've been around for 80 or 100 years, let's ask a different set of questions. Valuation is an important. Not a differentiator. Valuation is a lot more important for companies that have been around for a long time than a brand new entrant to the public markets.
Speaker 2How much of those model inputs come from your own qualitative insights of what should matter?
Speaker 1The selection of factors is driven by the potential questions that can be asked, is driven by the investment team. That's a major. Area of focus for us on the research side. Once we present that list of factors to the algorithm, it's completely mechanically determined. A lot of times we'll have an idea about a factor as a new idea, help the model improve its forecasting, and the decision trees will simply say, nice try, guys, but I don't find a lot of profitable questions to ask about this factor. I'm going to ignore it. In terms of how does it decide to use the factors? In relation to all the other characteristics, that's 100% driven by the algorithm.
Speaker 2How do you go through the process of retesting a factor that's working to see if the market catches up or it no longer works?
Speaker 1We do occasionally remove factors from our modeling. The reasons that you do it are that first one where the factor no longer works for one reason or another, whether you were mistaken or whether markets have evolved. Occasionally we'll remove a factor if we add something new that captures a correlated underlying effect. An example of that first factor, we used book to price in our models going back to version 1.0 in 1991. But as markets evolved and more importantly, as the economy has changed, we saw less and less explanatory power to incorporating that in our model. And we've had an intuitive set of models. We've had a more intuitive sense of why that factor seemed to explain returns in data through the 1970s or 80s, but maybe doesn't work given how the intangible economy that's arisen in the decades since changes how companies trade on their book values.
Speaker 2In the process of going from book to price being an important factor to not being in the model, what's the process to toggle on and off compared to decreasing its efficiency? And what's the importance into the construction of the model?
Speaker 1It's very data-driven. The process of removing a factor from the model, it's just the inverse of the process of adding a factor to the model. When we have a sense that a factor is working less well, generally that sense comes from the fact that we don't observe decision-making being driven by that factor on a day-to-day basis. When we review our trades every morning, year after year, we don't observe decision-making. Year after year, we see fewer and fewer trades that are being driven by this one factor. That's the value of the glass box, of being able to understand what's driving the decision-making. When we have that intuition that a factor has decreased in efficiency, we'll run that research project and say, "Well, the model seems to be making less use of this over time. What if we made zero use of it? What if we removed it from the model?" Right. If we remove it from what we present to the algorithm, how does that impact our research results? How does it impact the returns and the risk that we generate from our back test? If we see that we can remove a factor from the model and have very little or no impact on portfolio outcomes over the course of decades, that gives us confidence that that's a factor that no longer needs to be there.
Speaker 2As you work through and test all these potential signals for your model, I'm envisioning peering into the glass box and seeing a huge piece of paper on the wall with all these decision trees and different questions and nodes that gets down to a signal somewhere. What does that ultimately look like in the sense of how many theses are at the top and work their way down into different nodes if you could actually visualize what's inside this glass box?
Speaker 1We started our decision tree journey with one tree over the years with faster processing power. In more advanced algorithms, we've been able to improve the forecasting by relying on algorithms that employ a forest of trees. Back in the one tree day, we would print out the tree and tape it on the wall of our trading room. Every time we were reviewing a trade, we would simply walk through the sequence of questions on that paper tree on the wall to help inform what specifically was motivating every trade that happened in our portfolio. We've built some tools, some analytical helpers to synthesize and summarize what's happening across the thousand trees. At the end of the day, you could go through that exercise. It would be tedious walking through tree by tree, whether anything has changed, specifically what. But we're working on the data updates that are driving every decision that happens in
Speaker 2the portfolio. And in one individual tree, to get from the top to the bottom, how many different decision points and nodes are there?
Speaker 1Typically, we ask between two and five questions in each tree. The reason we don't ask more questions is we found that as you ask questions deeper and deeper in the tree, you're working on smaller and smaller pools. You're working on smaller and smaller pools of data because the trees are customized to the branch of the tree that you're working down. If you think about trees breaking up 50/50, at the second layer of the tree, each question is motivated on half of your original data. Down another layer, it's a quarter. Down 10 layers, each question is going to be motivated on one one-thousandth of the data. Down 20 layers, you would be operating on one one-millionth of the data. You can quickly see that there's a sharp limit to how deep you want to go. You can easily see how deep you want to make these trees. Fortunately, we have another approach to asking more questions about companies, which is rather than relying on a very deep tree, relying on a forest of relatively shallow trees.
Speaker 2If you either took me back to that original tree or took one of the trees in the forest, I'd love you to walk through an example of what those two to five questions end up being as you tracked one company. What is a common company from the top of the tree to the bottom?
Speaker 1The questions, they're asked in sequence and in context. At the top of the tree, you're going to ask a question of all companies. You're going to want a question that is relevant to explaining returns for big companies, small companies, growth companies, value companies. A common question we'll ask at the top of the tree will be about a company's use of financing, whether they're issuing debt and/or shares or whatever. What is a common question to ask of any company? We find, as the academics have, that companies that are engaged in significant amounts of financing tend to underperform, and those that don't have better outcomes. Down both of those branches, the algorithm proceeds in the same way. For the companies with a high level of financing, it tries to figure out what are the right questions to ask to find good companies and companies that are underperforming. The algorithm finds that the companies that are underperforming are the ones that are doing the most damage to the company. The companies that are underperforming are the ones that are doing the most damage to the company. that particular set. of high alpha stocks on the financing side.
Speaker 2If you go down that next level, if you're on the financing need, good momentum, what might a next question be to determine in that subset, which companies are likely to outperform?
Speaker 1Typical questions would be about volatility. We tend to find momentum works better when it is consistent. When the stock price is rising in a consistent manner, it leads to better outcomes than companies that have one giant price move driving the momentum measurement. Company age also comes into account there. We find that momentum typically is more meaningful when you're looking at newer companies than companies that have been around for a long time. They're generally higher growth businesses. They are more often. Industries that are evolving. Knowing that the sentiment is strong around those companies is an even more positive indicator of future returns than knowing that a company that's been around for 100 years had a good quarter.
Speaker 2How do you decide at what point in time it's worth going down another level compared to ending the tree and having your signal at the third level or the fourth level?
Speaker 1The stopping rules on questions. Question asking are mechanical. The whole process is mechanical. In our models, we stop for two reasons. One is we have a hard limit at five questions. After you've asked five questions, you're done. There's also a limit that if you've asked a question and created a branch that has too small of a pool of data, that will also be a reason to stop. The questions don't have to break companies up 50-50. Occasionally, we'll ask a question about the extreme price returns, whether on the positive or negative side. Generally, there aren't that many companies that have extreme returns, but they're very interesting. We will see some questions that pull out relatively small.
Speaker 2So you can imagine this toggling back and forth of questions between fundamental data financing to pricing data, momentum, and then fundamental data back and forth that you could have these thousands and thousands of trees and different questions you could ask. How do you then. Create a portfolio from all those signals aggregating thousands of different trees.
Speaker 1We're going to use technology. We have a portfolio optimizer that we've built that takes into account a couple of key things as it is constructing portfolios every day. It takes into account the alpha forecasts. It's a precise numerical forecast that comes out of the decision tree model. We're taking into account risk management, we use a set of hard risk constraints that are consistent across all of our portfolios, as well as a statistical risk model predicting the volatility and the tracking error of a portfolio so that all else equal will prefer portfolios that have more consistent outcomes than portfolios that have volatile expected outcomes. We also take into account trading costs. We want to make sure that we're not repositioning the portfolio unless we think that the improvement that we're getting from an alpha and risk perspective will compensate us for not only the visible costs of trading of spreads and commission, but the less visible costs of market impact.
Speaker 2How do you assess the relative importance of the signal from the model to market impact in trading?
Speaker 1We have a trade-off that's embedded in the optimization that captures that dynamic. Market impact specifically where it intersects with the portfolio construction is in terms of number ones or ultimate position sizing. Companies that are less liquid will tend to have smaller overall positions in them, but it also impacts the speed of trading to get to those positions. The biggest, most liquid name in the world trade in some of our portfolios. It's easy to trade tens of billions of dollars of multi-trillion dollar stocks, whereas some of our strategies are involved with small companies. We run small cap strategies, we run a micro cap strategy. In those spaces, we deal on some very illiquid stocks and it's important there not only to think about the ultimate size of the position, but how quickly you trade to those positions.
Speaker 2Several of the things you mentioned along the way there is human judgment that's coming into play, whether that is the risk constraints in the model or news coming out about a company and say, "Well, that's not what the model's trying to signal." How do you think about the degree to which your human judgment should override anything that comes out
Speaker 1of the model? We take a data-oriented view on that. We try to put all of the potential overrides that we might make to the decision-making of the model as much as possible through the lens of data. When we're thinking about trades, we're thinking about specifically what data inputs lead into what factors that are driving the decision-making. When a company that we're trading has reported great earnings, we want to dig into, "Okay, well, how are those great earnings going to impact all of the factors in our model?" At the next level, how will those factors changing impact the decision-making that comes out of the trees? It's often the case that we're trading something and they've just reported great earnings, but we are buying them for reasons that have nothing to do with analysts' forecasts. Whether the analysts raise their forecasts a ton or whether they make modest gains, or the analysts raise their forecasts a ton or whether they make modest updates can be irrelevant for certain of the trading that we're doing in our portfolios. That's the value of the glass box, is being able to see how the decision-making is being made allows us to be precise in terms of how we think about potentially
Speaker 2stepping in and overriding the model. How do you think about the reflexivity of other quantitative participants in different models as it impacts what you're doing?
Speaker 1When we think about that reflexivity in the quant space, there's a tendency to conflate natural fluctuations, good performance, bad performance, with quant strategies, which can be true of any investment strategy, with the impacts from running a strategy with leverage. When people talk about the most famous quant blow-ups of all time, long-term capital management, the quant quake in August of 2007, what they're highlighting are events that were caused by a period of underperformance for a quant strategy, but were magnified by the use of leverage in those strategies. If long-term capital management hadn't been running a 50X leveraged strategy, they wouldn't have ended up in the trouble that they ended up with. Similarly, in the quant quake, the pay-to-earnings, the capital management, the capital management, the capital paper that was published on that was written by Andrew Lowe, who's famous from MIT, and a gentleman by the name of Amir Kandani, who in a The World is Small anecdote, happened to be my roommate at the mobile internet startup that I worked at in college. But the run on quant strategies that happened was predicated by the fact that statistical arbitrage strategies had gotten more crowded over the years leading up to 2007. In response to that, certain managers began running those strategies with additional leverage. And leverage doesn't just blow up quant strategies, it's equal opportunity. No one panics out of traditional portfolio strategies. When Archegos blows up last year, there's a tendency for folks to think that quants are all one and the same. There's a lot of risk. Under the covers.
Speaker 2How much do you think about what your competitors are doing in an attempt to be the best you can be?
Speaker 1We don't spend a lot of time worrying about what our competitors are up to. Where we do tend to pay attention would be when competitors are publishing strategies that are specifically sounding like they're encroaching on our space, which is machine learning approach to traditionally looking investment, fundamentally based investment portfolios.
Speaker 2The impact of leverage on trading strategies to what we were talking about before feels like it may exist in the hedge fund pod shops today. And I'm curious if you've seen any changes in market structure that's impacting how you invest as those strategies have grown in size over the last bunch of years?
Speaker 1I wouldn't say that we, we have felt a huge impact from pod shops per se. It does feel like, the markets are different in the last couple of years than they were a decade ago. If you asked me five years ago, are markets on a never-ending trend towards efficiency? And is your job as a systematic investor going to get harder and harder and harder every single year? I would say absolutely, because that's the way it had gone for decades. Traditional factor tilting became commonplace. In order to have an edge, it got harder and harder every year. Something feels like it snapped in the last couple of years. I wish I knew what it was. It could be the rise of pot shops for all I know. It could be that we've hit a tipping point in terms of passive management in the equity space. It could be the rise of retail trading and meme stocks and Robinhood. It could be all of those things wrapped up in one. The good news is we don't have to worry about it. We don't have to worry about it. We don't need to know what's driving it. The important thing is having strategies that are active and that are able to take advantage of inefficiencies when they present themselves.
Speaker 2I'd love you to walk me through what your day looks like, because there's aspects of what you're talking about that are seeing what the model does. And then there's other aspects of observing the outputs based on a trade blotter. So as you go through a typical day in your life of managing your business, what do you see as the most important thing that you're doing? the portfolios? What does that path look like?
Speaker 1Every night we download updated data from all of our vendors. We recalculate all of our characteristics. We run all the companies in the domestic equity market through our forests and have updated forecasts. Every portfolio that we run is reoptimized and generates a trade list. The first thing every day is the trade review process. We're not doing trade review from the market. We're doing trade review from the market. But what we're after in that process is making sure, number one, that the data is correct. Then number two, to be able to understand the dynamics of the model and what's driving our trading. And also to make sure that there's not news out there in the marketplace that our data inputs do not see, but that we'll impact the market. And that's what we're after. A company and eventually probably will impact the data itself once it's updated. A company announces an acquisition. It can take upwards of a year of that deal closing. Once it closes, there's a lag until financial statements that reflect the deal are filed. We can get a jump on data by using our own eyes occasionally. The rest of the day for most of the team, the focus is on research. It's on idea generation. And execution on those ideas of thinking about how do we improve various aspects of our model. Being in the business since 1991, we pretty much use proprietary tooling for all the components of our process. Back in the 90s, there weren't third-party software vendors trying to sell you backtesting engines, risk models, trading cost forecast models. Everything that we use is built in-house. That gives us a lot of flexibility. A lot of flexibility and breadth in terms of the idea generation, what we can consider doing in terms of making enhancements to the process. It's not all about the factors that go into the stock picking, even though that's the most exciting part of research.
Speaker 2In that research piece, there's a wide swath of data on fundamentals and technicals, the stock price. Then you've had this whole explosion of alternative data sets. I'd love to hear what you think about that. How you've thought about the value integration of alternative data into your research.
Speaker 1In the markets, there are informational edges and there are analytical edges. It's not black and white between the two of those things. But generally speaking, when people get excited about big data, it's because they're excited about an informational edge. They're excited about finding some new source of information about companies and drive returns that maybe a lot of people don't know about yet. There are a lot of investors who are successful pursuing informational edges, but it can be a little bit of an arms race. These new data sources can be expensive. When too many people find out about them, depending on the size of the mispricing related to that data, the ability to generate returns can get diminished over time. We have intentionally focused not on that arms race, but on the analytical piece through the use of data. The data that feeds our models is oriented towards the longest historical data and the highest quality data sets that are out there in the quant space. So financials, prices, analysts, estimates. It's not to say that the big data explosion doesn't have any value. It certainly does. And lots of people are a testament to that. But it's important to know what your edge is. And for us, it's using the data that we're using to create the data that we're using to create these sophisticated machine learning tools to tease out differentiated insights about companies to have differentiated alpha sources. These algorithms are extremely data hungry. It's really important when you're building these machine learning models on noisy data, like forecasting equity market returns, to give them as much data as possible. We train our models on roughly 50 years worth of data, which I say that to some potential investors and they're surprised. But market data from the 1970s and 80s is still useful for forecasting this pricing. It is in the sense that these machine learning tools become more robust, the more data on more different market cycles and context of investing that they're able to be trained on.
Speaker 2When you've been working with machine learning models for a long time, what does the introduction of chat GPT change, if anything, in the way you've approached what you've
Speaker 1done? Large language models and chat GPT specifically are not anything that we're presently making use of in our modeling. One of the big challenges for folks who are trying to use those types of models in a stock picking context is the problem of in-sample versus out-of-sample. Especially if you're using a commercial model, you don't have any control over what data that model was trained on. When you're running a back test through the better part of the last decade, chat GPT knows that NVIDIA became a multi-trillion dollar company. Chat GPT knows what the mega trends were in the economy and the market over those timeframes. It's not realistic to trust a back test that chat GPT generated. That said, there are exciting things going on in the AI space. We use a lot of proprietary data. We use a lot of proprietary software and tools in our investment process. One area in AI that is really appealing to us is the idea of software development co-pilots. The idea that AI can make and enhance software development at an organizational level. We're a small team with a lot of software and any ways in which we can improve efficiencies there are valuable to us.
Speaker 2What new research are you excited
Speaker 1about? We are doing a lot of research in the factor space. We used to use stock ownership to drive some of our factors and that stopped working at a certain point. But we're coming back around to the idea that knowing who owns the stocks that you're contemplating investing in might be able to tell you something about how to evaluate opportunities there. We are also looking in the future to see what we can do in the future to see what we can do in the future. We're going to talk about some of the things that we can do in the future. We're going to talk about some of the things that enhance productivity, but also idea generation. It's probably still a ways off before we're asking large language models to suggest stocks for the portfolio. It's important to be open-minded about the possibilities. Computers are going to keep getting faster. Data is going to keep getting more and more prevalent and accessible. The algorithms are going to keep getting more powerful intersecting those two things. Even if something seems far-fetched today, that doesn't mean that it won't be 10 years from now and 20 years from now.
Speaker 2What do you find more challenging today than when you started your career?
Speaker 1One of the most challenging things is on the team building side. 20 years ago, talented data science-oriented programmers were not in demand by every single other firm. In the entire world, we had a much easier time finding junior analysts to join our team. Recruiting, given that the skill sets we're looking for are a lot more demand, has gotten more difficult. We've also tried to adapt and be more flexible in the types of people that we're looking for in response to that. In the same way that folks with data science backgrounds and AI knowledge are super in demand, the software programming space has hit a little bit of a soft patch. There's a lot of opportunities to hire great engineers these days. We're strategically trying to lean into where do we see the market for talent presenting opportunities to us.
Speaker 2What continues to excite you to keep you motivated to keep getting better?
Speaker 1The markets are exciting every single day. I've been at this for 23 years. We have learned a lot and improved our models significantly over those decades, but you're never going to solve the financial markets. There's always new information out there. There are always curve balls coming from a macro perspective, risks that you had never seen before that all of a sudden manifest themselves. From my perspective, it's a great place to be and a really exciting place to be applying my technical background to. Dan, I want to make
Speaker 2sure I get a chance to ask you a couple of closing questions. What is your favorite hobby or activity outside of work and family?
Speaker 1I am a home brewer. I took that up shortly after we bought our first house and I had enough space to store all of the equipment. We brew probably a dozen batches of beer a year, mostly trying to focus on what you don't find at the store all the time. My wife planted a sour cherry tree in our yard also at the time that we moved in. It's turned out to be wildly prolific, so we pull upwards of 80%. Pounds of cherries off that tree every year. I do her a favor by using some of them to brew interesting sour cherry beers.
Speaker 2Which two people other than your wife have had the biggest impact on your professional life?
Speaker 1I've worked at MDT my entire career and I was really fortunate to have two mentors from day one, David Goldsmith and Sarah Stahl. David was the founder of the Quant Group and the CIO. Sarah was one of David's first hires who led analytical, and portfolio attribution effort here for many years. What was great about the two of them was that they were incredibly different from one another in terms of mentors. David was the mad scientist of our group. He would be thinking about algorithms 24-7, come in and tell us about the idea he had while he was in the shower. Sarah was also very brilliant in a less wild and unconstrained way. She was very meticulous, very focused. On craftsmanship and understanding precisely what was driving the returns of our models. They were both great mentors and helped me appreciate that success in investment management. It's not all about being the brightest and having the most genius ideas. There are a lot of geniuses who failed. It's not just about meticulousness and craftsmanship, but both of those things are very important to success in this business. I'm really indebted to David and Sarah.
Speaker 2How's your life turned out differently from how you expected it to?
Speaker 1I would have never expected that 23 years on from graduating college that I would still be a quant working at MDT Advisors. We go through an exercise every couple of years, my graduating class, where we publish a book on what everyone's been up to the past five years. I think it's just me and a fellow who's worked at Microsoft for 23 years, who, who have gone down the career route and stayed in one place. It's been a phenomenal ride over the decades. The career that has managed to grow with me at every step where I needed it, I'm really fortunate that things turned out this way, even though I would have never guessed it.
Speaker 2Dan, last one. What life lesson have you learned that you wish you knew a lot earlier in life?
Speaker 1I've always been an incredibly competitive person. When I was young, I would take setbacks very hard. Frankly, I see that in my kids. They come by the competitiveness, and it's hard for them every time a little thing goes wrong. I wish I knew earlier on the life is a journey and that no one wins everything. Often, doors that seemed closed open in time. Sometimes the path that you end up on as an alternative ends up being the right path. I try to stress that with my kids as much as I can when I see them having the same struggles.
Speaker 2Dan, thanks so much for sharing your insights on this quantitative approach to investing. My pleasure. It was a great conversation. Thanks, Ted. One of the slots.
Speaker 3An important disclaimer. Views are as of November 2025 and are subject to change based on market conditions and other factors. These views should not be construed as recommendation for any specific security or sector. Investments involve risk and may lose value. Past performance is no guarantee of future results. There could be no assurance that quantitative investing will be a successful investing approach. The quantitative models and analysis used by MDT may perform differently than expected and negatively affect performance. Investing in equity and equity investing is a speculative and involves substantial risk. Diversification does not assure a profit nor protect against loss. Forward-looking statements or projections are subject to certain risks and uncertainties. Actual results may differ from those expressed or implied. Alpha measures excess returns of an investment relative to the return of a benchmark index. MDT Advisors is a federated advisory company.

Podcast Summary

Key Points:

  1. Daniel Marr is head of MDT, Federated Hermes' $26 billion quantitative equity group, which he joined in 2002 and has led since 2008.
  2. MDT uses a "glass box" decision tree framework that blends transparent, interpretable machine learning with human oversight, rather than a black box approach.
  3. The firm focuses on analytical edge rather than informational edge, favoring long-history, high-quality data over expensive alternative data arms races.
  4. Machine learning pitfalls like overfitting and underfitting are managed through a forest of shallow trees trained on roughly 50 years of market data.
  5. Human emotion is a key reason the strategy works, as even quant investors struggle to buy stocks with bad stories that the model identifies as undervalued.
  6. Dan traces his path from flipping hot IPOs as a Harvard student to building quantitative models, learning discipline from early losses.
  7. Leverage, not quant strategies themselves, caused famous blow-ups like LTCM and the 2007 quant quake, and market structure has shifted in recent years.
  8. Recruiting data science talent has become harder, and the firm remains open-minded about future AI applications like software development co-pilots.

Summary:

Daniel Marr, head of MDT, Federated Hermes' $26 billion quantitative equity group, discusses his career path and investment approach with Ted Seides on Capital Allocators. Dan began flipping hot IPOs as a Harvard undergraduate, an experience that taught him the value of disciplined, systematic investing after early losses from straying beyond his expertise. He joined MDT Advisors in 2002, working closely with founder David Goldsmith, and took over leadership in 2008.

MDT pioneered a decision tree approach in 2001, evolving from simple factor tilting to a sophisticated machine learning framework. Dan describes this as a "glass box" rather than a black box, emphasizing transparency so the team understands what drives every trading decision. The firm uses a forest of shallow trees, typically asking two to five questions per tree, to avoid overfitting while capturing nuanced interactions among factors like financing, momentum, volatility, and company age.

A central theme is the role of human emotion. Dan recounts how his head of trading regularly wanted to override purchases of stocks down 70-80%, illustrating why the strategy works: even quantitative investors struggle to buy bad stories. MDT focuses on analytical edge rather than informational edge, training models on roughly 50 years of data. Dan also discusses leverage-driven quant blow-ups, changing market structure, recruiting challenges, and his passion for home brewing sour cherry beers.

FAQs

MDT believes a disciplined, quantitative approach to stock picking provides an analytical advantage for all-weather portfolio returns. It relies on diversification rather than predicting market environments.

A decision tree is a series of yes/no questions about company characteristics that lead to a return forecast. MDT uses a forest of shallow trees to avoid overfitting.

The glass box means MDT's machine learning models are transparent, allowing the team to see how decisions are made. This contrasts with black box models where the logic is hidden.

MDT balances model complexity to avoid overfitting, which captures noise, and underfitting, which misses explanatory power. They use a forest of shallow trees and train on roughly 50 years of data.

Company age is how long a company has been publicly traded or filing financials. It provides context for which questions to ask about a company, not a direct return signal.

MDT uses a proprietary portfolio optimizer that considers alpha forecasts, risk constraints, statistical risk models, and trading costs to build portfolios daily.

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